package main

import "fmt"

func main() {
	str := "A"

	//其实没什么必要这么写！！

	switch {
	case len(str) == 0:
		fmt.Println("len(str) == 0")
	case str == "A":
		fmt.Println("str is A")
	case len(str) == 1:
		fmt.Println("len(str) == 1")
	default:
		fmt.Println("default..")
	}

}
